i use a 4 x 36 belt sander. with it i can make leather tools and knives, woodworking tools etc, sharpen anything under the sun i use a 1000 grit belt oiled to hone my stuff, and i can also make very awesomely flat and smooth edges on my leather projects all with just a change of a belt in seconds. Probably the most versatile tool in my shop. i have belts from 60 to 1000 grit and for wood, leather and iron.
Plus ima thinking i can make a cotton canvas belt for burnishing, got some planning and a holiday to get through first.
and it cost less, than one of those wheels that do only one thing.